The invention is in the field of mechanical engineering and precision engineering and can be used to particular advantage in apparatus which are conveyed to a deployment site in a transport state and are there brought into an operating state before they are started.
This is, for example, sensible with devices which have to be conveyed to sites which are difficult to access in order to be used there, for example pumps or machining tools in contorted hose systems or pipe systems.
In the microscopic scale, such devices can be used as microinvasive devices, for example pumps or rotary cutters in human or animal vessels, for example blood vessels or other bodily cavities.
In this respect, it is difficult to introduce these devices through the body's own vessels since the corresponding dimensions have to be kept very small for this purpose, with simultaneously larger dimensions being sensible in operation for the efficiency of use.
In the field of catheter pumps, in particular of blood pumps, radially compressible pumps have already been proposed to solve this problem which are kept in a transport state with small radial extent during transport and which can be radially expanded at the deployment site, for example in a ventricle, after introduction there.
For this purpose, complex and/or expensive mechanical constructions are known which serve the erection of conveying elements of a rotor. In addition, it is often necessary to stabilize the corresponding conveying elements such as conveying blades in operation since they are exposed to considerable fluid forces in operation.
A compressible rotor is known, for example, from U.S. Pat. No. 6,860,713. In addition, a further rotor is known from U.S. Pat. No. 7,393,181 B2. In the solutions known from the patent literature, provision is made in part that a rotor is compressible by elastically deformable conveying blades or that erection mechanisms for conveying blades are provided which are otherwise laid at the side of the rotor when it is stationary.
In addition to the compressibility of the rotor, it can also be advantageous or sensible to configure the pump housing, which can surround the rotor, in a correspondingly compressible manner.
In this respect, there is as a rule the problem that, on the one hand, the construction and the materials of the rotor should be stable in operation in order reliably to convey the fluid at high speeds and that, on the other hand, a certain yielding of at least parts of the rotor is desirable to keep the forces which are necessary for the compression of the rotor or of the pump within limits.
A technique is known from WO 2009/132309 to bring stents into a desired form after the introduction into a blood vessel by introducing a hardenable medium and subsequently to stabilize them in an operating state.